Jeep 1996 Grand Cherokee Service Manual - page 1164
CONDITION
POSSIBLE CAUSES
CORRECTION
4. Overrunning Clutch Worn/Broken.
4. Inspect and check for debris in oil
pan. Repair as required.
5. Oil Pump Components Scored/
Binding.
5. Remove, inspect and repair as
required.
6. Output Shaft Bearing or Bushing
Damaged.
6. Remove, inspect and repair as
required.
7. Clutch Operation Faulty.
7. Perform air pressure check and repair
as required.
8. Front and Rear Bands Misadjusted.
8. Adjust bands.
DRAGS OR LOCKS UP
1. Fluid Level Low.
1. Check and adjust level.
2. Clutch Dragging/Failed
2. Air pressure check clutch operation
and repair as required.
3. Front or Rear Band Misadjusted.
3. Adjust bands.
4. Case Leaks Internally.
4. Check for leakage between passages
in case.
5. Servo Band or Linkage Malfunction.
5. Air pressure check servo operation
and repair as required.
6. Overrunning Clutch Worn.
6. Remove and inspect clutch. Repair as
required.
7. Planetary Gears Broken.
7. Remove, inspect and repair as
required (look for debris in oil pan).
8. Converter Clutch Dragging.
8. Check for plugged cooler. Perform
flow check. Inspect pump for excessive
side clearance. Replace pump as
required.
NO 4-3 DOWNSHIFT
1. Circuit Wiring and/or Connectors
Shorted.
1. Test wiring and connectors with test
lamp and volt/ohmmeter. Repair wiring
as necessary. Replace connectors
and/or harnesses as required.
2. PCM Malfunction.
2. Check PCM operation with DRB scan
tool. Replace PCM only if faulty.
3. TPS Malfunction
3. Check TPS with DRB scan tool at
PCM.
4. Lockup Solenoid Not Venting.
4. Remove valve body and replace
solenoid assembly if plugged or shorted.
5. Overdrive Solenoid Not Venting.
5. Remove valve body and replace
solenoid if plugged or shorted.
6. Valve Body Valve Sticking.
6. Repair stuck 3-4 shift valve or lockup
timing valve.
NO 4-3 DOWNSHIFT
WHEN CONTROL
SWITCH IS TURNED OFF
1. Control Switch Open/Shorted.
1. Test and replace switch if faulty.
2. Overdrive Solenoid Connector
Shorted.
2. Test solenoids and replace if seized or
shorted.
3. PCM Malfunction.
3. Test with DRB scan tool. Replace
PCM if faulty.
4. Valve Body Stuck Valves.
4. Repair stuck 3-4, lockup or lockup
timing valve.
ZJ
TRANSMISSION AND TRANSFER CASE
21 - 25
DIAGNOSIS AND TESTING (Continued)